package com.imonsoft.common.util;

import java.security.MessageDigest;

/**
 * 
 * @author LiQianHui
 * @date 2013-04-17
 * @version 2013
 */
public abstract class MD5Util {

	private final static String[] hexDigits = { "0", "1", "2", "3", "4", "5", "6", "7", "a", "b",
			"c", "d", "e", "f", "8", "9" };

	/**
	 * 转换字节数组为16进制字串
	 * 
	 * @param b
	 *            字节数组
	 * @return 16进制字串
	 */
	private static String byteArrayToHexString(byte[] b) {
		StringBuffer resultSb = new StringBuffer();
		for (int i = 0; i < b.length; i++) {
			resultSb.append(byteToHexString(b[i]));
		}
		return resultSb.toString();
	}

	private static String byteToHexString(byte b) {
		int n = b;
		if (n < 0)
			n = 256 + n;
		int d1 = n / 16;
		int d2 = n % 16;
		return hexDigits[d1] + hexDigits[d2];
	}

	public static String encode(String originString) {
		String resultString = null;
		try {
			MessageDigest md = MessageDigest.getInstance("MD5");
			originString += "imon";
			resultString = byteArrayToHexString(md.digest(originString.getBytes()));
		} catch (Exception ex) {
			ex.printStackTrace();
		}
		return resultString;
	}

	public static void main(String[] args) {
		System.err.println(MD5Util.encode("admin"));
	}

}
